Your 1100 can handle steel, and it will through normal choke tubes. I would advise using Improved Cylinder. Special steel choke tubes tend to last longer, however. Unless your gun is the 3-inch magnum model, you'll have to stick to 2-3/4-inch shells, regardless of the barrel. You might also consider using other nontoxic shotshells. I've found 2-3/4-inch steel loads to be much less effective than 3-inch loads--and neither is as effective as 2-3/4-inch shells using Bismuth, Tungsten-Iron, or Hevi-Shot. They cost more, but you'll use less ammo to down birds. The least expensive duck load is Bismuth's nonbuffered load with No. 5 shot, but when I'm after geese I prefer Federal's Tungsten-Iron or Remington's Hevi-Shot in No. 4.